Smithsonian.com

Air Pollution as Seen From the Skies

From Mt. Etna to China to the Sahara, these striking satellite images of air pollution are from both natural and man-made causes

(NASA)

April 19, 2010

8 of 8

A Florida Red Tide

(ESA)

When some algae proliferate, or “bloom,” they can produce chemicals that are toxic to other marine organisms. One of the best known of these algal blooms is the red tide off the Gulf coast of Florida, which was first observed by Spanish explorers in the 1500s. Nearly every summer, Karenia brevis algae reproduce in great numbers and produce a dangerous chemical, brevetoxin, that kills fish, contaminates shellfish and, when aerosolized, smells revolting and makes breathing difficult for people near the water.